As the day's cricket unfolded below, a police helicopter hovering to the Southwest of St John's Wood was an almost constant presence on a grey, autumnal day at Lord's. The chopper was, of course, helping the authorities keep an eye on the Notting Hill Carnival - perhaps the second biggest street festival in the world behind Rio's - but as Middlesex cantered to a seven-wicket win over Sussex in a match with practically nothing at stake for them on a gloomy day, it very much re-enforced the feeling that the real action was elsewhere.

Middlesex quickened their chase to a sprint towards the end, Paul Stirling thrashing an unbeaten 46 in double-quick time after openers Sam Robson and Dawid Malan had set an almost impregnable platform, but the victory in front of a smattering of home supporters was very much consolatory. Indeed, the only really vocal support all day came from Sussex's travelling contingent.

Sussex have, of course, already qualified for the semi-finals of the competition but missed the opportunity for a home tie with a defeat to Kent last week, while Middlesex crashed out of the completion on net run-rate despite joining Sussex at the top of Group A.

With little pressure and not much more than pride to play for, both sets of openers profited against the hard, new ball on a placid pitch. Ed Joyce and Chris Nash racked up a fluent 90 in partnership before they were parted but Robson and Malan went even farther, rattling along past 150 at a-run-a-ball as neither seam nor spin found much joy.

Amjad Khan, the quickest bowler of the day on either side, did at least manage to keep things tight and cause the odd moment of alarm but Chris Liddle was dealt with easily and Wayne Parnell's solitary wicket came at the cost of 58 runs in seven overs. Monty Panesar, the lead spinner out of the four slow bowlers played by Sussex, could neither contain nor break through.

Malan, one of only two Middlesex batsmen to pass 500 runs in this competition (the other being Stirling), was the main aggressor and first to reach fifty, from just 48 deliveries. Robson joined him not long after, from 53 balls, and Malan looked set for his second List A hundred of the season when, having cracked 10 crisp fours and a six, he flashed at Parnell to be caught behind for 84 in the 26th over.

One over later, Robson heaved across the line at Michael Yardy and was bowled for 64, and it appeared Sussex might have an opening. They were unable to sustain any pressure, however, and a typically boisterous Stirling took the attack to the bowlers to finish the match with almost three overs to spare.

Nash had begun Sussex's day in similar fashion, taking four fours off Anthony Ireland's second over - the third of the game - and depositing Robbie Williams into the second tier behind straight midwicket before five overs had been bowled. At the ten-over mark Sussex had rushed to 69 for 0, Joyce very much playing second fiddle to Nash, who reached a 38-ball half-century with a drive to deep cover.

He departed soon after, playing across the line to be bowled by Jamie Dalrymple, but Joyce nudged Sussex towards 150 with a fifty of his own. After he had been suckered by Malan's increasingly useful part-time legspin, each member of the middle order managed to keep the momentum up, Yardy and Joe Gatting putting on 54 for the fifth wicket before Gatting departed to the penultimate ball of the innings.

Middlesex now turn their sights towards their Division Two promotion hopes, while Sussex will be thinking ahead to a semi-final away from home.